Induced earthquakes are natural phenomena in which the events are associated with human activities. Although the magnitudes of these events are mostly smaller than tectonic events, in some cases, the magnitudes can be high enough to damage buildings near the event's location. To study these (high-magnitude) induced events, we developed a workflow in which the recorded data from an earthquake are used to describe the source and monitor the area for other (potentially high-magnitude) earthquakes.

A fiber-optic cable was installed along a freely suspended rod in a deep geothermal well in Munich, Germany. A cold-water injection test was monitored with fiber-optic distributed acoustic and temperature sensing. During injection, we observe vibrational events in the lower part of the well. On the basis of a mechanical model, we conclude that the vibrational events are caused by thermal contraction of the rod. The results illustrate potential artifacts when analyzing downhole acoustic data.

We investigate the capability of distributed acoustic sensing (DAS) to record dynamic strain changes related to Etna volcano activity in 2019. To validate the DAS measurements, we compute strain estimates from seismic signals recorded by a dense broadband array. A general good agreement is found between array-derived strain and DAS measurements along the fibre optic cable. Localised short wavelength discrepancies highlight small-scale structural heterogeneities in the investigated area.

This work investigates the impact of commonly used seismic interpretation methods on the analysis of faults. Fault analysis refers to fault length, displacement, and the impact these factors have on geological modelling and hydrocarbon volume calculation workflows. This research was conducted to give geoscientists a better understanding of the importance of interpretation methods and the impact of unsuitable methology on geological analyses.

We use seismic, electromagnetic, and geoelectrical methods to assess sediment thickness and lake-bottom geology of two karst lakes. An unexpected drainage event provided us with the unusual opportunity to compare water-borne measurements with measurements carried out on the dry lake floor. The resulting data set does not only provide insight into the specific lake-bottom geology of the studied lakes but also evidences the potential and limitations of the employed field methods.

In the first kilometers of the subsurface, temperature anomalies due to heat conduction rarely exceed 20–30°C. However, when deep hot fluids in the shallow crust flow upwards, for example through permeable fault zones, hydrothermal convection can form high-temperature geothermal reservoirs. Numerical modeling of hydrothermal convection shows that vertical fault zones may host funnel-shaped, kilometer-sized geothermal reservoirs whose exploitation would not need drilling at depths below 2–3 km.

This paper shows the results of seismic interpretations that document the presence of large Upper Jurassic carbonate buildups in the Miechów Trough (S Poland). Our work fills the gap in recognition of the Upper Jurassic carbonate depositional system of southern Poland. The results also provide an excellent generic reference point, showing how and to what extent seismic data can be used for studies of carbonate depositional systems, in particular for the identification of the carbonate buildups.

Time-domain electromagnetic (TEM) geophysics data originally collected for mining purposes were reprocessed and inverted. The new inversions were used to construct a 3D model of the subsurface geology to facilitate hydrogeological investigations within a DANIDA-funded project. Improved resolutions from the TEM enabled the identification of possible paleovalleys of glacial origin, suggesting the need for a reevaluation of the current lithostratigraphy of the Voltaian sedimentary basin.

This paper presents MuLTI-TEM, a Bayesian inversion tool for inverting TEM data with independent depth constraints to provide statistical properties and uncertainty analysis of the resistivity profile with depth. MuLTI-TEM is highly versatile, being compatible with most TEM survey designs, ground-based or airborne, along with the depth constraints being provided from any external source. Here, we present an application of MuLTI-TEM to characterise the subglacial water under a Norwegian glacier.

Land–river reflection seismic, hydrogeological modelling, and magnetic investigations in an area prone to quick-clay landslides in SW Sweden provide a detailed description of the subsurface structures, such as undulating fractured bedrock, a sedimentary sequence of intercalating leached and unleached clay, and coarse-grained deposits. Hydrological properties of the coarse-grained layer help us understand its role in the leaching process that leads to the formation of quick clays in the area.

The alluvial fan of Ghor Al-Haditha (Dead Sea) is affected by subsidence and sinkholes. Different models and hypothetical processes have been suggested in the past; high-resolution shear wave reflection surveys carried out in 2013 and 2014 showed the absence of evidence for a massive shallow salt layer as formerly suggested. Thus, a new process interpretation is proposed based on both the dissolution and physical erosion of Dead Sea mud layers.